• Proceedings of the Korean Magnestics Society Conference
• /
• 2003.06a
• /
• pp.92-93
• /
• 2003

• Proceedings of the Korean Powder Metallurgy Institute Conference
• /
• 2006.09b
• /
• pp.915-915
• /
• 2006

• Proceeding of EDISON Challenge
• /
• 2013.04a
• /
• pp.221-223
• /
• 2013

Self-assembly of the molecular system of perylene-3,4,9,10-tetracarboxylic-3,4,9,10-dianhydride (PTCDA) and the amide analogue (PTCDI) is of potential importance for organic semiconductor devices. Therefore we studied the density of states (DOS), the charge densities, and intermolacular bond lengths for PTCDA and PTCDI using the density functional theory calculations.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2010.11a
• /
• pp.505-506
• /
• 2010

• 한국정보디스플레이학회:학술대회논문집
• /
• 2004.08a
• /
• pp.975-977
• /
• 2004

According to thin and light form-factor and additional function of today's electronic devices, it is required to decrease the pattern pitch of FPC. The high density demand is more and more important trend especially, for small size LCD module. Based on this requirement, the manufacturing process is advancing from subtractive method to super subtractive method.

• JSTS:Journal of Semiconductor Technology and Science
• /
• v.14 no.5
• /
• pp.549-556
• /
• 2014

This paper proposes a highly power-efficient single-inductor multiple-outputs (SIMO) DC-DC converter with a gate charge sharing method in which gate charges of output switches are shared to improve the power efficiency and to reduce the switching power loss. The proposed converter was fabricated by using a $0.18{\mu}m$ CMOS process technology with high voltage devices of 5 V. The input voltage range of the converter is from 2.8 V to 4.2 V, which is based on a single cell lithium-ion battery, and the output voltages are 1.0 V, 1.2 V, 1.8 V, 2.5 V, and 3.3 V. Using the proposed gate charge sharing method, the maximum power efficiency is measured to be 87.2% at the total output current of 450 mA. The measured power efficiency improved by 2.1% compared with that of the SIMO DC-DC converter without the proposed gate charge sharing method.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2004.05a
• /
• pp.115-118
• /
• 2004

The phase transition between amorphous and crystalline states in chalcogenide semiconductor films can controlled by electric pulses or pulsed laser beam; hence some chalcogenide semoconductor films can be applied to electrically write/erase nonvolatile memory devices, where the low conductive amorphous state and the high conductive crystalline stale are assigned to binary states. AST(AsSbTe) used to phase change material by applying electical pulses. Thickness of AST chalcogenide thin film have about 100nm. Electrodes are made of ITO and Al. $T_c$(Crystallization temperature) of AST system is lower than that of the GST(GeSbTe) system, so that the current pulse width of crystallization process can be decreased.

• Transactions on Electrical and Electronic Materials
• /
• v.16 no.1
• /
• pp.16-19
• /
• 2015

A wearable sensing ECG T-shirt for ubiquitous vital signs sensing is proposed. The sensor system consists of a signal processing board and capacitive sensing electrodes which together enable measurement of an electrocardiogram (ECG) on the human chest with minimal discomfort. The capacitive sensing method was employed to prevent direct ECG measurement on the skin and also to provide maximum convenience to the user. Also, low power integrated circuits (ICs) and passive electrodes were employed in this research to reduce the power consumption of the entire system. Small flexible electrodes were placed into cotton pockets and affixed to the interior of a worn tight NIKE Pro combat T-shirt. Appropriate signal conditioning and processing were implemented to remove motion artifacts. The entire system was portable and consumed low power compared to conventional ECG devices. The ECG signal obtained from a 24 yr. old male was comparable to that of an ECG simulator.

• Journal of Power Electronics
• /
• v.11 no.4
• /
• pp.430-438
• /
• 2011

This article proposes a robust nonlinear control based on Lyapunov's redesign, whose purpose is to deal with parametric uncertainty in the resistance of the motor windings. The robust controller design is based on the passivity properties of the motor, as well as energy shaping and damping injection. The application of this control technique is focused on electric vehicles mainly formed by a battery bank, a power inverter, an AC brushless motor and the mechanical transmission. The sine PWM technique is used to trigger the switching devices of inverter. The results were obtained from simulation, where is shown that robust control makes a proper tracking of electromagnetic torque.

• Current Photovoltaic Research
• /
• v.2 no.3
• /
• pp.110-114
• /
• 2014

We propose a low temperature sol-gel ZnO/Ag nanowire composite thin film to fulfill low temperature and low cost requirements, which are essential criteria in future flexible electronic devices. In this proposed thin film, Ag nanowire plays the role of electrical conduction, and sol-gel ZnO provides a structural medium with a high visible transmittance. Low temperature restriction in the sol-gel fabrication process prevents sufficient oxidation of Zn acetate precursors, which were solved by a post-coating treatment with ultraviolet light irradiation. Composite thin film formation was performed by spin coating methods with a mixed precursor solution or in a sequential manner. We obtained an average visible transmittance larger than 85% and a sheet resistance smaller than $50{\Omega}/sq$. After optimization in a fabricated composite transparent conductive thin film with the thickness around 100 nm. Similar experimental demonstration in a flexible substrate (polyethyleneterephthalate) was successful, which implies a promising application opportunity of this technology.